Currently, a network element (NE)-based architecture is used in an evolved packet core (EPC) network. Typical network elements included in the architecture include a mobility management entity (MME), a serving gateway (Serving Gateway, S-GW), a packet data network gateway (P-GW), and the like. Currently, by using a service feature and processing logic that are built into a network element and a procedure message between network elements, the EPC network implements corresponding network functions, for example, implements functions such as mobility management, bearer management, and location management.
With continuous expansion of business models and continuous development of mobile communications technologies, a user business needs more service models and better service features, and therefore brings a requirement for a new network function. Network functions provided by a conventional EPC network are built into and distributed on network elements. Therefore, if a new network function is introduced in the EPC network to support a service requirement of a user, the EPC network needs to redefine and redesign processing logic and a procedure interaction of the network elements. However, a network element architecture of the conventional EPC network has difficulty in supporting network function extension. It is difficult to dynamically adjust, for example, newly add, update, or delete, a network function based on ever-changing user requirements, and it is difficult to meet a requirement of the user for a new use case.
For this purpose, a service-oriented architecture (SOA) may be used in a mobile communications network to resolve the foregoing problem. A basic architecture of the SOA is designed based on principles of function isolation and service layering. As shown in FIG. 1, a network function may be divided into a service consumer layer, a business process layer, a service layer, a service component layer, and an operating system layer. A service consumer may customize a needed service, such as a first service requested by a user shown in FIG. 1. Then a service chain in a business process is formed. The service chain then selects a proper service by using the service layer. A corresponding service component is determined based on the selected service. Then an application in the operating system layer is determined based on the determined service component. Finally, the network function is implemented by using the application.
The SOA can associate, by using interfaces and protocols defined among a plurality of service units, the service units that implement a network function; but is independent of a device, a hardware platform, an operating system, and a programming language that implement the network function. Therefore, a loose coupling feature of the SOA enables the mobile communications network to dynamically adjust, for example, newly add, update, or delete, a network function in the mobile communications network in a modular manner.
However, in the mobile communications network in which the SOA is used, when a network function is implemented, a core network and each external entity need to interact with each other by using a protocol. There are many types of interaction protocols, such as the S1 Application Protocol (S1 AP), the non-access stratum (NAS) protocol, the Diameter protocol, or the General Packet Radio System (GPRS) Tunneling Protocol (GTP). In addition, to enable the core network to complete a network function, in a business processing process, a service component in the core network needs to perform a plurality of message interactions with an external entity, and different interaction protocols are used in different message interactions. As a result, the service component needs to implement and maintain a plurality of protocol interfaces, thereby resulting in high design complexity of the service component and increasing difficulty of maintenance in a late phase.